Synthesis, characterization and antibacterial activity of some new complexes of Cu(II), Ni(II), VO(II), Mn(II) with Schiff base derived from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one

Abstract

Abstract Coordination compounds of Cu(II), VO(II), Ni(II), and Mn(II) with the Schiff base obtained through the condensation of 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one with 3-formyl-6-methyl-chromone were synthesized. The characterization of the newly formed compounds was done by 1H NMR, UV–Vis, IR, ESR spectroscopy, elemental analysis and molar electric conductibility. The crystal structure of 1-phenyl-2,3-dimethyl-4-(N-3-formyl-6-methyl-chromone)-3-pyrazolin-5-one (HL) has been determined by X-ray diffraction studies, as well as the one of its copper(II) complex [CuL(OAc)]·CH3OH which contains an anionic ligand and an acetate in the coordination sphere of the metal. The single crystal X-ray structure for (HL) was analyzed for its various weak H-bonding and dimeric association. The in vitro antibacterial activity against Staphylococcus aureus var. Oxford 6538, Klebsiella pneumoniae ATCC 100131, Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 9027 was studied and compared to the activity of the free ligand.